Problem: In the figure, a circle with radius $4\text{ ft}$ is inscribed in a square. What is the area of the square? [asy] size(150); draw((0,0)--(4,0)--(4,4)--(0,4)--cycle); draw(Circle((2,2), 2)); [/asy]
Explanation: The side length of the square is equal to the diameter of the circle inscribed inside. The diameter is twice the radius, $2\times4\text{ ft}=8\text{ ft}$, so the area of the square is $8\text{ ft}\times8\text{ ft}=\boxed{64}\text{ ft}^2$.